When a browser goes looking for a document that a user has requested, it first has a domain name server translate the domain name entered to an IP address. The browser then sends the user's request to the IP address. As of HTTP 1.1, the browser must also send to the web server the domain name that the user entered; it's no longer to be implied. This requirement makes virtual hosting possible. If Apache has no vhosts, it will use the main server's DocumentRoot directory (often set to /var/www/html). However, if Apache has been configured for vhosts, it will compare the client's request to the ServerName of each vhost with the same IP address and port that the request came in on. The accompanying vhost directives of the first ServerName that matches the client's request will be applied.
Within a vhost block--between